Rho Ophiuchi Region

Here's another image I took early this year using the Canon EF 200mm f/2.0L. As usual, to improve stars in the corners, I stopped down to f/4.0. Given the limited time and low altitude of this region from 45N, I was limited to just thirteen exposures. I used a modified Canon 5D2 at ISO 800 with exposures of 480 seconds. This was taken in early May before determining ISO 1600 was a better compromise between total time and noise.